Latch



J. H. SHAW LATCH Oct. 23, 1928. 1,688,472

Filed March 50, 1923 IIIIIIIIIIIIII4 y l' spring. The protraction or snapping ot the t JOHN' E, straw, or NEW HAVEN, .CoNNECTrCUT, assieme1t'rc sfuaanNmfa4 COMPANY, v i oFNEw-HAVEN,CoNNnCrrrCU T' f a .II-.Aron hlplication inea Marchdjsz serial-No. 628,755.

This invention relates to latches, and more Isuch that these elements will serve asa dashv55 particularly to .a latch designed to be used fpotto check the protraction of the latch bolt upon doors of p'ublic buildings ,`suc as hotelsl by its-spring, particularly during they latter or hospitals, where it is ydesired tov have the part Iof its movement, and, while permitting 5 closing of doors attended by the'least possible" the latch'boltto-snap -outwardly to a certain noise.. j X extent to take into the strike plate, willcause 60 It 's'common in door'locks or latches inruse the latter part of. the movement of thebolt at the present time'to provide a springfpressed to take place slowly so' as to eliminate, as far latch which is ordinarily cammed b'y the as possible, the objectionable noise which usu- .10 `door strike into retracted position when the l21115 -CCOmpIlieS the protract-ion of the latch.

, door is closed, and which snaps into pro- To theseva-nd other ends, the invention con-` 65 tracted position to ltake into the door strike ys ilsts in the novel features and .combinations whenthedoor has been closed, the pro'traction Ofparts to be hereinafter described land f being brought labout by the action ot the ClaimedI l.'

In the accompanying drawings:

latch boltinto the strike is nearly always .at- Fig! l S l IOII elevational ,View of a latch 70 I tended by a sharp click, which isusually embodying my improvements,thecover of the caused by the engagement with a part of the ltCh CaSe havmg been removed; llock case ot a crosshead on the latch or the t NFlg- 2 1S a Sectional view on line 2-2 o stemof' the bolt', lwhichengagement'serves to Flg: 1;

limit the distance to which the bolt may be' Flg- 3 1S 'el SEClOHal View 011 lille 3-3 0f 75 protracted by the spring. Regardless, how- F12- 1; f ever, of the cause, this noise' is particularlyI v'Flgn 4 1s a view Islmllar' to Fig. 2, but shownoticeable where a number of rooms open into 1h52 lh@ ltch' ,holt/ 1n .ltsletlacted POSQH; one corridor, and is. especially annoying in lFlg- 5 1S a detail VleW 0f the Cylinder 0f the hotels or hospitals wherev it is ,desirable to daShlfJOt; 2 i y i Apreserve absolute quiet; and, in the case of Flg- 6 1S 'a'detall YlQW nl lhe latch'holta hospitals, where people must often necessar- 'ShOWlng the manner 1n Whlch the plunger iS ily pass in and out'ot the doors of the rooms ttafhed theretOnd 1l j `v atnumber of times each day, this sharpclick f Flg- 7 1S a Sectlonal YleW n'llln 7 7 0f which accompanies the shutting of one door Flgl- A y v j u S5 after4 another is extremely annoying to the In th? Prefelle@ embodiment/'0f my lnVeI1-- pafent n l tion wh1ch I have lllustratedm the drawings,

@ne object of my invention is to overcome the latch mEX he 0f any usual 011 'Preferred the disadvantage hereinbefore pointed `outin fonmf @Omplslng the latch C359 l2 111 Which S ,a the door locks in use at the present time, and l'eclprocablymouhted a latch hOlt COIHPIS- 90 to provide a ylatch which will be extremely' lng the holt head 13 and the SGIH 14- Th@ quiet in Operation. f l stem 1s guided between .a-pairbf posts '16 Another object of my inventionis to` proi WhlCh may he mad@ lnteglfl Wlth the Case vide the latch boit of a dominee with a yield-z 'and betwe'enthese posts and a washer 1'?7 adv inel check or buffer which. while allowing the .laCeht th? hOlt heall, 1S POSltlOned the usual 95 y bolt to be protracted to the usualeXtent, will latch Sprlng 18, YVhlCh Serves t0 PIOICt the prevent the 4noise or clicking sound which latch lnt? the S-l'lflle Plate (noli-Shown), When ordinarily `accompanies such protraction.- the door upon Whlch the latch-'1S mounted' 1S Still another object of mv invention is to Closed- 1 '4 l provide thelatch bolt of a door latch with a ,Any Sultable. means may-,be PlGVldedlOl' 100 yielding check to resist the action of the latch Wlthdmwmg the lfltch holt nil/0 the Case the' f spring and to cause the latch bolt to be promeans ShOWh COIlSlShlhg 0f a Tetl'cflllg yOle 'tracted slowly and softly by this spring, p ar- 19 normally Urgell tOWalfFl th f OIWaId face 5 ticularly during the latter part of its I nove- 0f the lOC'k Case hy 31 SPllngQO, and adapted ment. to be drawn rearwardlyby a knob-operated 105 More particularly, Ispropose to provide a roll back 2l. In'the 1atCh Sh0Wnthe I'ecooperating .plungenand cylinder uponthe tracting yoke is provided withv a 'finger 2 2, lock case and a movable part of thelatch bolt, 'which engages the crossh'ead 23 secured `to CII 'or the lower post 16. It will'be apparent that some' such limiting means is necessary'to pre'. vent the'latch being thrown too far forwardlly and thus dislodgedfrom its guides.;l Reardless ofthe particular form in which. this imiting means is provided, .the protractiojn bolt when the ldoor is Vclosed and the bolt is protracted int-o the strike plate by itsspring, the movement o fthebolt is accompanied by asharp clicking sound which is" generallycausedA by the engagement of the which engagement serves to prevent a -fnrther outward movement of the latter.- I proose to provide a buffer or check for the latch olt which, while permitting the limiting lmeans to function as before, will bringLabout va practically noiseless operation vofthe latch .boltand lwill eliminate the clicking Isound heretofore referred to.

In the preferred form of my invention which I have illustrated 1n the drawingsthis check or buHer takes the form oflwhat may be termed a dashpot, end comprises a cylinder 25 and a cooperating piston 26. yAs shown in the drawings, 'the cylinder is secured vto the latch case and the piston is secured to a part of the latch bolt to move therewith,` al-f y though, if desired, it is entirely within the scope of my invention to reverse the arrange- `ment of the 4parts and connect-the cylinder tothe blt and the piston to the latch case. The connection between the cylinder and the latch case is established by means vof a .lug

2 7 being attachedto the cylinder and-provided with a keyhole slot 28 adapted to fit over a post. 29 secured rigidly to the latch case and provided with aI laterally` extending lug 30 to fit intofthe neck 31 of the key hole' slot, soas to prevent `any tendency of the cylinder to rotate upon the post 29. This post may be the usual one provided'in locks of this character, against which react the springs 32 of Lthe tumblers 33 -of Athe usual latch bolt 34. It will, of course, beunderstood that any other; arrangement forse-curing the cylinder.

to the latch case may be provided if desired.

Thecrosshead 23 of the latch bolt is', as

' shown i theV drawings, extended somewhat .at one s'de of the bolt stem, and to this extended endthe plunger 26 may be secured by anydesired means, suc a's-riveting or l upsettingthe end thereof'onthe'side opposite Ithe bod ofthe plunger'. The plunger is provide Vwith a .slightly'enlarged head 35 which 1s adapted to make a close t within 'the bom se @f the Cylinder. 'i niwili be noted. that, while the bore of the cylinderis of conv'stant diameter for some distance outwardly` V'from the closed `endv 37, the mouth .ofthe -bore may be flared to some extent, as shown iat' 38 to provide for the easy entry! of the r head 35 tothe plunger therein, thisflaring surfaceacting as a guiding surface to prop- 'erly guide the plunger into thatV part of the cylinder where it fits closely. ,The operation of my 'device is as follows:

t When the door is closed, the latch bolt is end oi'mouth of the cylinder. Upon the closling of the door, whenthe head 13' of `'the bolt reaches the point opposite the opening in the y door "strike, the bolt will immediatelyy ber stops or other means with a' part of the bolt,r

urged to Jprotracted positionfby its spring 18.

It 'will-be apparent that during the initial part' of ythe movement o f the bolt'by its spring,

there will be practically no resistancemto such action, the head35 ofthe plungerA merely slidinwloosely along 'the inclined wall 38 ofthe cylinder. This, allows the bolt'to be protracted .the door strike andalso permits the spring "to overcome the inertia of the parts and to gather momentum tocomplete the` protrac-l -to a suflicient extent to take into is of vuniform diameter andf ingly checked 'by the elastic action of the air confined between the head of the piston andthe closed end of. the` cylinder. Although checked suitably in velocity, the movement of f the bolt will continue due tothe further com- I l ression of the air within the cylinder and to the escape of thisair about the head 35 of the- This latterpart of the. movement plunger.

v'of the-bolt, however, which is checked in this manner, will t-ake place 'more lor .less slowly and will result in the crosshead 23 engaging the post 16 `very lsoftly -so as to practically eliminate the noise which usually accompanies such engagement.

no i

.In Figs. 1 andy, I have Shown a. theek of similar construction to cushion the return movement of the door retract-ing yoke 19. In

this instance, the cylinder 40 may be provided with a perforated tongue 41 to engage the end of a post gr'b'olt 42 of the latch to hold the cylinder in position. The plunger 43 is provided with a .slot 44 in which is fitted a tongue 45 Secured to or' made integrally with the yoke 19. The tongue 45 andv slot'44 may loe of dove-tail shape, so that the tongue may notk be withdrawn longitudinally from the slot, but any suitable means to connect the tongue A* to the-plunger may, of course, l

this instance, it Will be noted Ithat thebore of the cylinder 40. is of. constant diameter throughout its length, although' it may be -made with a -laringv mouth ysimilar to the cylinder 25, if desired, 'and,"conversely the bore of the cylinderl may be of constant diameter throughout its length like the cylinder 40. In either case Where the'cylinder is provided witha liar-ing mouth or Wherey it is .of constant diametcr,the bolt Will usually be permitted a limited movement before the e effective checking operation begins, Las the vbolt stem 14 or the retracting yoke 19 will be lmoved to the left, as shown in Fig. 1, by their respective/springs, until ,theair inthe cylinders is sufliciently compressed to overcome the action of these springs. It Will, of course', be

,apparent that as the springs areyextended,`

their force becomes lessened and, inversely. as the plunger-s approach the ends of the cylmder, the checking force becomes greater. For

these reasons, the retracting yoke 19, as Well 4elastic check or bulier to resist the action of this spring. [It will be understood, therefore, that When theexpression bolt controlling member is used in the claims, reference is made to either the stem 1 4 or the yoke 19.

'I have preferred to show a check or buffer" for the door latch which is in the form of a pneumatic check or dashpot, but it will, of

' course, be obvious that other forms Will readily suggest themselves to those skilled in the art.

While I have shown and described a preerred embodiment of 'my'inventiom it will be understood that it is not limited to all the details shown, but is capable of many modifications and/ Variations Which lie Within the -spirit of the invention' and Within the scope of the appended claims.

What I claim is:

1. In a door latch, -a case, a spring protracted latch bolt having a stem, va erosshead upon said stem, means to 'engage the crossyhead to limit the 'protraction of the bolt, a

plunger attached to saidcrosshead, acylinder mounted in the latch case and adapted to receive the plunger when the bolt is protracted.

2. In a door latch, a case, a spring protracted latchbolt having-,a stem, a crosshead upon said stem, means to engage the crosshead to limit the protraction of the bolt, a plunger connected to the crossheadland lying substani `tially parallel with the bolt stem, and a-cylinder to receive said plunger when the bolt is protracted.

" 3. In .a latch, acase, a reciprocable latch 'bey usted. rn-

'protracted position, 'and pneumatic means in of the bolt.

means Within the' latch to prevent a noisy enbolt therein, including'a head and astem, spring means within thecase to urge said bolt to protracted position, and means within the case to engage said stem to silence xthe protrae# tion of the ,bolt by the spring. 70 4. In a latch, aacase, a reciprocable latch` bolt therein, including a head and a stem, spring means to urge said bolt to protracted position, and means to engage said stem to resist the action of the spring to silence the protraction of the bolt. f f

l5.'In a latch, a case, a reciprocable latch bolt therein, vincluding ahead and a stem, spring means in the case to urge said bolt to the case to engagesaid stem tojresist the action of the spring to silence the protraction f of the bolt.

6. In a latch, a case, La reciprocable latch bolt therein having an enlarged head and a stem reduced in size, 5means to /retract said bolt, spring means surrounding said. stem t-o return said bolt to protracted position, and a check ymounted in the'ease to retard the return 7. Ina latch, acase, areciprocable latch Y bolt therein, .means to retract said bolt ineludingv a'bolt actuating member, and pneu- ,l

matic means within the, case to retard the movements of said bolt and said member in one direction i 8. In a latch, a case, a retractable and Iprotraetable latch bolt therein, said bolt havin a portion thereof extending 'through said oase adapted to be engaged by external means '100 to retract the bolt', means within the 'case to engage a part of the bolt to limit its movement to protracted position, and a silencing gagement of said-parts.'

9. Ina latch, a case, a retractable and protractable latch` bolt therein, said bolt having. a portion thereof,- extending through said case adapted'to beengaged by external means to retract the bolt, means Within the case to', en- 110 gage apartv ofthe bolt to limit its movement to protracted position, and means Within the latch to cushion the engagement of said parts.

v'10.. In a latch, a case, a' retractable and protractable latch bolt therein, vsaidbolt having a portion thereof extending through said case adapted to be engaged by external means to retract the bolt, means Within the case to ngage a part of the bolt to limit its movement to protracted position, and pneumatic means Within the latch to cushion the engagement of said parts.

1l. In a latch, a case, areciprocable latch bolt therein, manual means :to retract said bolt, automatic -means to ret-urn the bolt to protracted position when said manual'means is released, and a buil'er Within -the case to cushion the return of thebolt.

12. In a latch, a case, a reciprocable latch .,bolttherein, manual means to retract' said 13 bolt,- automatic` means to protracted psition when said manual is released, means to engage apart of the bolt to limit its return movement,l and ,a buffer within the case to cushion the engagement off' said means with the bolt. 13, In a latch, a reciprocable latch bolt, manual means to retract said bolt, automatic means'to-retnrn the bolt to protracted position when said manual means lis released, means. to engage a part of the bolt to-llmit its return movement, and a dashpot buffer to cushion the engagement of said means with thelbolt.

14. In a latch, a reciprocable latch bolt, spring means to protract saidbolt, meansto yieldingly bolt by said springm'eans, sald checking means permitting a -free action of the spring during the first part of the protractmg move- .ment, but resisting the action of said springh during the latter part of the movement.

15. In a. latch, a case, a i'ecprocable latch; bolt therein, manuallyl Aoperable means to retract said bolt within ,theI latch, -and 4recheck the protraction'ofl the said bolt to protracted position;

re'tnrn the 'bolt Vto' :tarded acting means Within thecase tmove means vf 16; In'A a latch, a' case, a protractable latch", .n bolt therein, manual means to retract thefmovcment -of they bolt -to protracted position.

V 17.,In a latch, a case, a protractable latch bolt therein, manual-means toretract the bolt, and,y a buffer lI'nech'anism I A cushiony the-movementof the bolt to -protrac'ted position.

. 18. In a latch,

a case,-

protractable vlatch within the caseto bolttherein, manual means toretract'the bolt and pneumatic means within .the case'` to cushi ion the movement of the bolt to protracted positionI 19. Ina latch, acase,la protractable latch bolt therein, manual-means to retract the bolt including a boltactuating member, and a silencinglmeans Within the case to cushionthemovement of thebolt to protracted position-f i and the return movement of saidmember.

,"In Witness whereof, Il have hereunto set my hand on the 19th day'of March, 1923.

' ,f JOHN n. SHAW.' 

